SimCity 4 Rush Hour is an expansion pack for SimCity 4. Propably known as other name in some cuntries. You can buy it in a shop or via internet. It's really good to get becouse you can now drive cars, trains etc., you can build avenues and you can see informations about traffic in your city/town. In box versions (or in online versions too) it's availible in SimCity 4 Deluxe edition.